Last year I was taking pictures at my oldest sons graduation party. Scores of young adults and formal gowns and tuxedos. I shot for 2 hours...even got some killer shots inside the limo, which had a disco-ball and a light-show going on. I knew I had some Grade-A shots of my first son's graduation, his friends and beaming parents.

As I returned home, I eagerly inserted my SDHC non-brandname card, which had never failed me before. After tranferring 30 out of 850 shots, it stops..gives me an error message..and..dies. First time that ever happened to me..and I'll make damn sure that it's the last, if I have something to say about it...lol. No amount of data-recovery software could help me.

Since then I have changed to a camera that use CF cards and I only use brand-name cards.

Sure, if you want to save some of your hard-earned money, grab a few of the cheapies for the casual walk-about shooting where you can live with the loss of a few hundred shots. That makes sense...but I encourage you to keep one or two that are top-notch grade-a cards for those shoots where it matters!

If I cry about anything photography-related it's because of something so beautiful that it claws at your soul..lol..that time it was for entirely different reasons!!..and I'm still pissed about it too!!. I keep the card glue to my monitor stand as a reminder..hehe..

Considering that there are only a handful of flash memory chip makers, the difference is in the controller and the flash memory chip used.
There are different quality grading of the flash memory chips and different performance grades.
However, most of the big brand names should be very similar and imho, SanDisk is over rated, BUT they do have more quality control over their products as they manufacture the actual flash memory chips, something most companies don't with the exception of Micron (Lexar/Crucial) Samsung and Toshiba.
Personally I really like Toshiba's cards, they're very fast and reliable.